SLO Residential Properties Can Save Money

It's that time again!  The Sewer Cap Period for the 2023–2024 year (for residential properties only) is approximately December 3* through March 9. Your usage during this period will determine your sewer cap for the 2024–2025 year, so make sure to turn off your irrigation!

During these months the days are shorter, the weather is typically cooler, and there is more moisture in the air. Even in years where there is less rain than usual, using these months is still the best measurement we have of calculating your average impact on the sewer system.

For more information on drought related impacts on winter water use, see Council Agenda Report dated May 6, 2014 and Resolution No. 10587.

*Due to delayed meter reads the sewer cap period began December 14, 2023. Staff may adjust the calculation to reflect the sewer cap period more equitably. 

Sewer Cap Process

You may have noticed that your bill contains consumption charges for both water and sewer. While the City measures all water consumption by metering the water that is delivered to each property, we are unable to meter the wastewater or sewer that is collected through the drains in your sinks, toilets and showers. 

Since residential properties are restricted from having separate landscape meters, water consumption can be higher in the summer months due to landscaping and other outdoor, warm weather activities. In order to prevent charging residents for sewer usage for water that is used outdoors, the City of SLO caps units of sewer that can be charged based on minimum annual consumption.

How it Works

Determining the Sewer Cap

To compensate for this difference in usage, the City instituted the Sewer Cap for residential customers.* Water usage is tracked from December through February when irrigation systems are likely off. The usage is averaged to determine the sewer cap applicable for the upcoming year.** For example: 

In this case, the Sewer Cap will be set at 5. Once the Sewer Cap is determined, it becomes effective July 1 of that year. This Sewer Cap will apply to the customer’s account for the entire year, until the following July, when the new sewer cap will be established anew.

Sewer Cap Implementation

The Sewer Cap sets the maximum that a customer will be charged for wastewater treatment (sewer) per month. The amount a customer is billed each month is based on their usage up to their cap. For example, using the sewer cap of 5 determined above:     

 * Sewer Caps apply only to residential properties. Commercial and industrial customers who are concerned they may be paying sewer costs for irrigation may opt for a dedicated landscape meter installed at their own expense.

 ** The Sewer Cap defaults to 5 units for new customers that do not yet have an established sewer cap (4 units applies per dwelling for multi-family properties like duplexes and apartment buildings on a single meter).